Influence of cirrhosis on outcomes of patients with advanced intrahepatic cholangiocarcinoma receiving chemotherapy

International audienceBackground: Cirrhosis is a risk factor for intrahepatic cholangiocarcinoma (iCC). However, its exact prevalence is uncertain and its impact on the management of advanced disease is not established.Methods: Retrospective analysis of patients treated with systemic chemotherapy for advanced iCC in the 1st-line setting at 2 tertiary cancer referral centres. Cirrhosis was diagnosed based on at least one element prior to any treatment: pathological diagnosis, baseline platelets <150 × 109/L, portal hypertension and/or dysmorphic liver on imaging.Results: In the cohort of patients (n = 287), 82 (28.6%) had cirrhosis (45 based on pathological diagnosis). Patients with cirrhosis experienced more grade 3/4 haematologic toxicity (44% vs 22%, respectively, P = 0.001), and more grade 3/4 non-haematologic toxicity (34% vs 14%, respectively, P = 0.001) than those without. The overall survival (OS) was significantly shorter in patients with cirrhosis: median 9.1 vs 13.1 months for those without (HR = 1.56 [95% CI: 1.19-2.05]); P = 0.002), confirmed on multivariable analysis (HR = 1.48 [95% CI: 1.04-2.60]; P = 0.028).Conclusion: Cirrhosis was relatively common in patients with advanced iCC and was associated with increased chemotherapy-induced toxicity and shorter OS. Formal assessment and consideration of cirrhosis in therapeutic management is recommended

Influence of in-plane damage on out-of-plane behavior of laminated composites and bonded assemblies

Les matériaux composites sont utilisés dans le domaine maritime depuis des dizaines d’années que ce soit par exemple pour les éoliennes offshore ou encore les navires militaires étant donné leurs propriétés intrinsèques avantageuses pour de telles applications (faible masse, faible signature magnétique ...). Jusqu’ici les composites employés sont surtout composés de fibres de verre et de matrice polyester. Cependant, les demandes croissantes de navires toujours plus légers et rapides conduisent peu à peu les industriels à se tourner vers les composites à haute performance composés de fibres de carbone et de matrice époxyde. L’utilisation de cette nouvelle génération de matériau nécessite de connaître l’influence de l’endommagement plan, qui peut être d’origine hydrique ou mécanique, sur leur tenue hors-plan. Cette étude a montré une diminution importante de l’enveloppe de rupture du matériau étudié lorsqu’il a séjourné en eau de mer jusqu’à saturation. La résistance en traction hors-plan du composite n’est quant à elle que très peu affectée par la présence de fissures transverses dans le matériau, quel que soit son état de vieillissement. Des travaux ont également été menés sur des assemblages composites collés et mis en avant à la fois la chute de la tenue de l’assemblage due à la présence d’eau de mer dans la matrice époxyde, mais également la nécessité de la prise en compte du couplage endommagement plan/endommagement hors-plan pour la prédiction de la tenue hors-plan de tels assemblages. Enfin, différentes méthodes de prédiction ont été utilisées pour valider les résultats expérimentaux confirmant ainsi l’importance de la prise en compte de l’endommagement plan sur la tenue hors-plan des composites et des assemblages composites collés.Composite materials have been used in marine applications for decades for offshore windmills or even battleships because of its intrinsic properties which are assets for such applications (low weight, low magnetic signature...). Until now the composites used are almost made of glass fibers and polyester matrix. However the increasing demand for faster and lighter ships gradually leads manufacturers to turn to high performance composites made of carbon fibers and epoxy matrix. Using this new generation of material requires knowing the influence of the in-plane damage which can be due to water or mechanical damage on its out-of-plane strength. This study has shown a significant reduction of the out-of-plane failure envelope of the studied material after an extended stay in seawater until the saturation point.The out-of-plane tensile strength of the composite is very little affected by transverse cracking in the material whatever the aging state. Work has also been carried out on composite bonded assemblies and pointed out, on the one hand, the drop of the assembly strength because of the water aging and, on the other hand, the necessity to take into account the coupling between in-plane and out-of-plane damage for the prediction of the out-of-plane strength of such assemblies. Finally, different methods of prediction have been used to validate the experimental results confirming the importance to take into account the in-plane damage to predict the out-of-plane strength of composites and composite bonded assemblies

Influence de l'endommagement plan sur le comportement hors-plan des composites stratifiés et des assemblages collés

Composite materials have been used in marine applications for decades for offshore windmills or even battleships because of its intrinsic properties which are assets for such applications (low weight, low magnetic signature...). Until now the composites used are almost made of glass fibers and polyester matrix. However the increasing demand for faster and lighter ships gradually leads manufacturers to turn to high performance composites made of carbon fibers and epoxy matrix. Using this new generation of material requires knowing the influence of the in-plane damage which can be due to water or mechanical damage on its out-of-plane strength. This study has shown a significant reduction of the out-of-plane failure envelope of the studied material after an extended stay in seawater until the saturation point.The out-of-plane tensile strength of the composite is very little affected by transverse cracking in the material whatever the aging state. Work has also been carried out on composite bonded assemblies and pointed out, on the one hand, the drop of the assembly strength because of the water aging and, on the other hand, the necessity to take into account the coupling between in-plane and out-of-plane damage for the prediction of the out-of-plane strength of such assemblies. Finally, different methods of prediction have been used to validate the experimental results confirming the importance to take into account the in-plane damage to predict the out-of-plane strength of composites and composite bonded assemblies.Les matériaux composites sont utilisés dans le domaine maritime depuis des dizaines d’années que ce soit par exemple pour les éoliennes offshore ou encore les navires militaires étant donné leurs propriétés intrinsèques avantageuses pour de telles applications (faible masse, faible signature magnétique ...). Jusqu’ici les composites employés sont surtout composés de fibres de verre et de matrice polyester. Cependant, les demandes croissantes de navires toujours plus légers et rapides conduisent peu à peu les industriels à se tourner vers les composites à haute performance composés de fibres de carbone et de matrice époxyde. L’utilisation de cette nouvelle génération de matériau nécessite de connaître l’influence de l’endommagement plan, qui peut être d’origine hydrique ou mécanique, sur leur tenue hors-plan. Cette étude a montré une diminution importante de l’enveloppe de rupture du matériau étudié lorsqu’il a séjourné en eau de mer jusqu’à saturation. La résistance en traction hors-plan du composite n’est quant à elle que très peu affectée par la présence de fissures transverses dans le matériau, quel que soit son état de vieillissement. Des travaux ont également été menés sur des assemblages composites collés et mis en avant à la fois la chute de la tenue de l’assemblage due à la présence d’eau de mer dans la matrice époxyde, mais également la nécessité de la prise en compte du couplage endommagement plan/endommagement hors-plan pour la prédiction de la tenue hors-plan de tels assemblages. Enfin, différentes méthodes de prédiction ont été utilisées pour valider les résultats expérimentaux confirmant ainsi l’importance de la prise en compte de l’endommagement plan sur la tenue hors-plan des composites et des assemblages composites collés

Comparison of cohesive zone models used to predict delamination initiated from free-edges : validation against experimental results

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A simple characterization methodology for the identification of the visco-elastic behavior of thermoset adhesives during cure

International audienceThe identification of the mechanical behavior of adhesives is necessary to describe the development of residual stresses during their curing, which might impact their mechanical strength and lead to early failure of the bonding. A simple characterization and modeling approach is therefore developed and presented, which permits to monitor and identify the mechanical behavior of a thermosetting adhesive during the whole curing process. The test method is based on a compressive test, which consists in applying a periodic displacement and recording the subsequent load variations during cure. The test set-up relies on a simple apparatus as it consists in steel cylinders mounted on a standard tensile test machine. The analysis of the mechanical behavior is based on an analytical description of a visco-elastic constitutive law following the Maxwell model, leading to the identification of the material apparent viscosity and Young’s modulus. This characterization methodology is applied to an epoxy adhesive during cure. The obtained mechanical properties are in good agreement with values provided by the material supplier, which permits to validate the developed methodology

A 3D model to analyze the behavior of composite laminates subjected to out-of-plane loadings

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Determination of the 3D failure envelope of a composite based on a modified Arcan test device

International audienceThis paper describes a 3D failure criterion identified through Arcan tests, to analyze the behavior of a laminate composite subjected to out-of-plane loadings. The proposed criterion is based on the Hashin’s hypothesis and the interactions between tensile and shear out-of-plane loadings are taken into account. The out-of-plane stresses generated in the composite subjected to an Arcan test are studied using 3D Finite Element calculations in order to determine the stack sequence influence. Using different angles of the loading and different stacking sequences allows the ply to be subjected to complex 3D stress state. Using the experimental results and an inverse identification procedure, it is possible to identify the out-of-plane failure envelope. It is shown that a quadratic failure envelope, which takes into account a decrease of the apparent shear strength in the presence of out-of-plane tensile stress, permits the model to describe in a correct manner the experimental results

Chemical features of floodplain soils under different land-uses in the Solimões/Amazon River basin

Texto completoMost studies regarding the impacts of agricultural systems on soils of the Amazon region of Brazil have been carried out on upland soil, locally known as terra firme. Information regarding the impacts of different land-use systems on floodplain soil properties is still scarce. There is a need to broaden this knowledge to understand this Amazonian ecosystem better, especially how its soils respond to human interventions. This study aimed to describe the major chemical features of floodplain soils along the Solimões-Amazon Rivers and the effects of different land-use systems on soil nutrient levels. Sixty-two different land-use systems were sampled in 15 communities located in three different regions of the Solimões/Amazonas River floodplain complex: Upper and Middle Solimões (UMS), Lower Solimões and Middle Amazon (LSMA), and Lower Amazon (LA). Soils under cultivation showed a high availability of Ca 2+ , Mg 2+ , and P and low levels of exchangeable Al, in contrast to soils under forest and secondary vegetation, which were more acid and showed higher levels of exchangeable Al. Although most of the samples showed high contents of K + , for some areas, the low level (K + <0.15 cmol c kg -1 ) of this nutrient can become limiting to crop production. The low levels of N found in most of the analyzed samples confirm that this element may be the limiting nutrient for agriculture in floodplain ecosystems. The use of legumes and other nutrient-rich plants, which naturally occur in the Amazon floodplain environments, could potentially address this N deficiency in these soils

Unresectable HCC patients disposal in the new era of immunotherapy from the elitor study based on the french chief cohort

International audienc